18949988 has 6 divisors (see below), whose sum is σ = 33162486. Its totient is φ = 9474992.

The previous prime is 18949949. The next prime is 18949993. The reversal of 18949988 is 88994981.

It can be written as a sum of positive squares in only one way, i.e., 11343424 + 7606564 = 3368^2 + 2758^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2368745 + ... + 2368752.

It is an arithmetic number, because the mean of its divisors is an integer number (5527081).

Almost surely, 2^18949988 is an apocalyptic number.

It is an amenable number.

18949988 is a deficient number, since it is larger than the sum of its proper divisors (14212498).

18949988 is a wasteful number, since it uses less digits than its factorization.

18949988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4737501 (or 4737499 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 56.

The square root of 18949988 is about 4353.1583936264. The cubic root of 18949988 is about 266.6058326509.

The spelling of 18949988 in words is "eighteen million, nine hundred forty-nine thousand, nine hundred eighty-eight".